By Dr. Becker
As global temperatures rise, there are signs that the animal kingdom is making adjustments to perhaps support its survival. Research has revealed, for instance, that corals, fruit flies, chickens and fish experience epigenetic changes in response to heat.
Epigenetic changes affect how genes are expressed, essentially turning “on” or “off” various genes in response to environmental cues (without changing DNA sequence).
Researchers with the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin, Germany have now revealed that such epigenetic changes also occur among mammals, a sign that climate change may affect many, if not all, species through “environmental epigenetics.”1,2
Guinea Pigs Show Epigenetic Changes in Response to Heat
Researchers set out to determine if male wild guinea pigs can adapt epigenetically to an increase in temperature and whether that adaptation would be passed on to their male offspring.
The animals lived and mated at an ambient temperature lower than 5 degrees C (41 degrees F). They then spent two months living (and mating) at 30 degrees C (86 degrees F).
At least 10 genes, particularly those involved in encoding proteins responsible for protection against heat damage, showed changes as a result of the temperature change.
Specifically, the genes showed significant differences in the methylation of the DNA, and the changes were passed on to male offspring. Alexandra Weyrich, researcher at the IZW, told Science Daily:3
"We believe that the transfer of epigenetic information from father to sons prepares the latter for changes in environmental conditions such as a rise in temperature.
This is particularly important with regards to a possible adaptive response to climate change. Epigenetic mechanisms could therefore be crucial for the fitness and survival of the offspring.”
Unlike changes to sequence of DNA, epigenetic modifications are flexible and can occur quickly to “switch on” or “off” genes in response to a changing environment. The research again confirms that some of these epigenetic changes are also passed on to future generations.
Other Species Adapt to Changing Climates
Many species are already feeling the effects of a changing climate. Polar bears, for instance, depend on ice floes (floating ice) to hunt seal, mate and give birth. As the sea ice melts, the bears may be forced onto land, where food is scarce.
On shore, the bears resort to eating goose eggs and even human trash, which may give them a small nutritional boost but is unlikely to sustain the species as a whole over time. The melting sea ice may also be encouraging the bears to spend more time in the water.
In Svalbard (part of the Norwegian archipelagos), researchers documented a record-breaking polar bear dive – three minutes and 10 seconds – made by an emaciated polar bear hunting a seal.4
The researchers believe the long dive may indicate the bears are resorting to extreme survival measures as climate change leads to less available ice.
Meanwhile, changes in climate may alter migration patterns and timing for monarch butterflies, birds and many other species. Scientists have also speculated that wildlife might change in size as a way to adapt to warmer, sometimes drier conditions.
It’s possible that climate change could alter gene activity or other biological processes to stunt the growth of certain animals.
Researchers from four U.S. universities concluded that climate change might be behind the shrinking size of certain salamanders in the Appalachian Mountains region of the U.S., for instance.
Top Changes in Wildlife and Ecosystems Due to Changing Climates
Climate change has been called “the biggest threat to the long-term survival of America’s wildlife.”
It’s said that 2012 was the warmest year on record in the U.S. and the National Wildlife Federation has released a series of reports on how wildlife and ecosystems are adapting to a “warming world.”5 Some of the top observed changes include:6
Changes in range, such as animals moving northward or to higher latitudes Widespread forest loss due to drought stress, insect infestations and more wildfires Coral bleaching, which occurs when algae that live in corals die (which will ultimately cause the coral to die, too) Melting of Arctic sea ice, which threatens the survival of polar bears, walrus and seals Loss of wetlands, which could threaten breeding areas for North American waterfowl Sea-level rise, which could erode coasts and diminish habitat for birds and other coastal creatures
While it appears many creatures, including wild guinea pigs, may be able to somewhat adapt to this changing environment, government and non-government organizations are calling for efforts to better understand, prepare for and address the impacts of climate change.
As noted by the National Fish, Wildlife & Plants Climate Adaptation Strategy:7
“Climate change affects more than temperature. Impacts include shifts in rainfall and storm patterns, catastrophic wildfires, and water shortages, as well as rising sea levels, loss of sea ice, ocean acidification, and coastal flooding and erosion.
These changes are already having significant effects on fish, wildlife and plants here in the United States, necessitating new resource management approaches for climate adaptation.”